Stuart Roy
Naval Architect & Consultant

Fellow of the Royal Institution of Naval Architects
Chartered Engineer

Email:  info@StuartRoy.co.uk
Tel.  44 (0) 1489-583346         Email:  info@StuartRoy.co.uk  
© Stuart Roy 2015    
The Self-Launching Powerboat
Possibly the world’s most versatile workboat
Faced with the problem of launching and recovering a powerboat over a steep shingle bank, inventor Shaun Maguire had the answer - a self-launching powerboat!  Aircraft carry their landing gear with them, so why can’t a boat?

I was delighted to be able to assist Shaun with the design and development of this unique patented concept, by designing the hull and construction for his 24ft aluminium powerboat. On land the boat travels on hydraulically powered caterpillar tractor units which can move independently in either direction to allow on-the-spot turns. A lifting nose wheel with wide pneumatic tyre supports the bow.

When afloat the tractor units are raised, again by hydraulics, and the hull bottom is sealed by shutting the hydraulically powered “bomb doors”. The nose wheel is lifted by a winch and the outboard motor takes over.  Powered by a 175 hp 4-stroke outboard motor, the boat was predicted to achieve speeds in excess of 30 knots.

During the design work a great deal of attention was paid to the weight and centre of gravity of the craft.  All the major components, including the tractor units are made from aluminium alloy to achieve an acceptable all-up weight and allow the boat to plane easily.

The tractor units were tested extensively carrying a platform equivalent to the all-up-weight of the finished boat and engine. The test rig managed to climb the beach without any problems so the next stage was to build a hull.

This hull for this amazing boat was built by Pepe Boats of Hayling Island, followed by fitting out and commissioning by Shaun Maguire. When in use the boat draws quite a crowd of amazed onlookers when it propels itself up and down the shingle bank and in to the sea.

On trials the boat achieved 29 knots at 4500rpm with a Suzuki 175hp outboard.  When the engine had completed its running-in period and could be taken up to full revs of around 6500 rpm, speeds of around 35 knots were achieved. The boat handles really well and appears to be exceptionally dry - excellent qualities for a multi-purpose workboat.

See some Video Clips on YouTube